High-frequency antenna matching device



March 2, 1954 R. R. WILLIAMS. 2,671,201

HIGH-FREQUENCY ANTENNA MATCHING DEVICE 2 Sheets-Sheet l Filed July 29, 1949 moa 229531.1-

IN VEN TOR. QALFH Q WI LUAMS iria@ ME 'f sd usr-NUWU OL..

March 2, 1954 R R, wlLLlAMs 2,671,201

HIGH-FREQUENCY ANTENNA MATCHING DEVICE Filed July 29, 1949 2 Sheets-Sheet 2 TO RECEIVER. NTENN A UOSTS TO POWER LINES OQ ANTENNA W :l 'Il m2 .n es g W a5 E 2% INVENTOR. DALDH QNILLIAMS vUNITED STATES PATE-NT.. olnnlcr.

HIGH-FQUCY-ANTNMTHING 7 U ,1)1.;v1oE-VA ,n ch i Application Jiy 29,.,1949,seialnolioais' V Y l@ flennimsa'fwteinen; fj?" 'W tThis invention relates to radiol receiverndilerent arrangements of the receiver input cirl tnnnnsyinnlslnnd more particularly t0 antenna. Cnitand. the antenna. as t0 bnlenningmatching means for use with highfregueny 'I o prevent signalloss due to the Ause of pure radio receivers, such as television receivers, FM: resistance in the matching network, the invention receivers'fa'nd the like. also contemplates theuse of coils in conjunctionobject ofthe invention `is to providean with the variable resistors and ground connecgfA` antenna-matching unit which acts as abalan tion, whereby better results are obtained in t 1 1e ing nieans so that high-frequency receivers` of elimination of not only ghosts caused by mis# vaiions input circuit impedancesof'the balanced match, but also ghosts caused by multi-prati)- orliinbalanced type maybe matched with antenna 1o transmission. The use of the coils, in the man;

systems oi` various impedances ofthe balanced ner to be presently described, provides -step-up,of oriunbalanced type. A the desired signal and attenuation of undesired lAffurther object of the 'invention'is top-rovde signals. a means for minimizing `secondary images, known Referring now to the drawings, and more parff,Y as ghostsj and other electrical disturbancesl.; ticularly to Figure yl, 11'and4124 designate thew present in the input circuit of television receiver s. outputv terminals of the antenna-matching cir- Eurther objects `and advantages or" the 'invencuit, said terminals being connected, as indicated, tionwill become apparent from the following to the receiver antenna posts.v Designated .at 1 4; description and claims, and from the accompanyand I6v are therespective input' terminalsfcon ingdrawings, whereinf 2o n ected respectively to the transmisison line wires 'f Figure 1 'is schematic wiring diagram of one I1 andi leading to the antenna, or to the housel form of antenna-matching system c0n'structed in wiring when said house wiring is employedin accordance with the present invention; place of an antenna; vDesignatedat l5' is anotherl ,Figure l-a is a schematic diagram illustrating input terminal which is connected to groundl'ffff. a'modication of the system of Figure 1,; 25 Designated at I9 is a variable resistor having vFigure 2 is a schematic Wiring diagram illusa movable tap 20. One 'of the xed terminals'o f tr ingano'ther form of antenna system' accordresistor I9 is connected Ato terminal Il. The" to the present invention; y l tap' is' connected by a wire 2| through a con- `'igure 3 isa schematic Wiring diagram illusdenser 2'2 to terminal I4. #Designated at22'is'" tr g still another 4form of antenna system ac another variable resistor having a movable tap c'ording tothe Apresent invention; `2 3."l`j One of the Vfixed terminalsof resistor 22 Vis` y Figure 4 isa schematic wiring diagram simi connected to terminal i2. The movable tapl 23" lar to Figurel, b ut illustrating a modification is connected by a wire 24 through'a condenser 25 thereof. 1 to terminal I6; @In viewof the fact that mis-match betweengg "Designated at 25 is another variable resistor the transmission line of 4an antenna system and h avingamovable tap 21. 'One xed terminal of4 theinput circuit of. a television receiver is one resistor 26is connected by a wire 28 through` a" ofitheyauses,offghosts it is ,the practice in condenser 2.9"to the ground terminal l5. "Th'el the art to vinsert Vin thetransmission line fixed othe'rfvfixed terminal of resistor 26 is connected resistors, in series and shunt, of predetermined '40 to the pole 30 of a single pole double-throw switch' vaines for .each specific oase, to match the arii 3|. One of the stationary contacts o'f's`vvitcli'3'l`,4 tenna'system with the input circuit of theteleshown at 32, is connected to Wire 2 l. The other vision receiver. However, a given arrangement stationary contact, indicated at 33, is connected oithis type isnot adaptable to all types of reby awire 34 to the terminal Il. The movable tap c""ers andantenna systems, since the input 45 27 iS Connected by a wire 35 to'thepOle 36 of circuits of v diierent receiversl have different ima single D016 dOUble-throw switch 31. One cone'dances, and different antenna systems lalso tact, 'shown at 3B, of said switch is connected to have ,:liierentl impedances. Furthermore,v some W1e124.' The other contact, shown at 39,`i`s c'onl.lv

receiver input circuits areof the balanced type, nected by a' wire'l to terminal I2. Y

While `others are ofthe unbalanced type, the 50 The' variable resistors i9, 22 and' 25" may saine being true of different antenna systems.k A `v`'have any' desired value. Preferably, however,A givenfized arrangementas abovedescribed is said variable resistors each vhas maxi-'I particularly unsatisfactory when employing the mum'value of 300 ohms, Con'densers 22',125and electrical wiring .system'ofa building as the 29 are low-frequency blocking condensers and" signal,collector.,4 'Ihereiore itv isa prime pur- 55 may be of the order of .00025 mfd., vof the mica.V pose` of vthe present invention to provide an ar- `type,' 2,20 fvo1ts working voltage-. vTlie condensers' rangementottheabove typeeniploying variable 22 and 25 may be omitted where thedevice is In Stine in @nninnc'ton With-nennen@ enncf nedlnrelyntheirenmssionilineOianeaistingf ns. asientan.; Ons-.enslandiffernn ref.. antennasysm, mit Qnnected.. t@ rh cnil nreliirlent .6s-,lightingsanguinshere '.c. 1

In operation, the movable taps 20, 23 and 21 are adjusted until correct matching of the input circuit of the receiver, connected across terminals II and I2'-,2to`tl1eantenna circuit,` connected across te'rninals I4 arid I6, is obtained. By'

means of the switches 3| and 31, the resistor 26 may be connected to the circuit on either side of'm' the resistors I9 and 22, as desired?? 'IliisfniaiLvv become necessary in balancing the various im-"i pedances of different antenna systems Witlrthe various impedances of the input circiiitso vari" ious receivers.

As shown in Figure La, the connections of tap 21 and terminal 28 of resistor 26 may'""be' relV versed from the connections shown in Figure l,

contee# ia'zi iseonnecredl by e Wire 42-4 through" d'.; oiitpiy 1 Mter-irrinals*"loeijnig-3 connected *toi4 tlie recive'if" posts? Designated at isa Variable" resister havinge nievebietee'zieeneetedbyj co enser' Z'Zwto the terminal-I4: Designatedat* a "a tf'fihformeriwmiiising en'rsrieeii Mena af'rsebond coil lin inductiverelation" with"cil "fj Eacli'coil niayfcompr'ise 12 turns of f18-gaiige wireftvoundona 1/gi-inch coilforrn. Coil 45""ispreferably) Wound' over said coil" All, alltljiougli rthe coil'sfrnaybe'Woundonseparatecoil 'iorinsf" The coils'fare center tapped, as shown at' lllarid'v Dsigriated'jat" I9 and 22f`ar`fhv'ariable resistors minall If. The "other terminal of said'coil is con# nctedto wire 42." The movable 'contazt"o'f' re`` sistor kI9iscoi1n`ected to the ceterfta'p v'116i One ledtercinal of said resistor isconnected td'Wie" 48. One terminal of coil 46 is Iconifiected''by Wirfiftdterrninal IZ'L The other terminalof connected' to `l Wirell.

AIt will be 'seeirthat improved'matchi'g"may be"o'btaine'd because of the' inductive'reactance' 4l wherebyL seid Contact 21 is connected te ground through" condenser 2`9. in veffect',`

provides'a variable shunt to? ground' of the rec'eive'r terminal 'i `I in` one position of switch pole 30;"orfof the transmission line 'terminalv I4`in the other positioii of 'switch Dole`30.'

Referring te Figui-e 3'z rsi t2' designate' the" output vterminals" of' the device; said outputter' mir'ils` being` connected "to tljfe` receiver antennaf Betweeivthe terminals*landwf'and" and 65 coupled with a second pair of intermeshed windings 66 and 61. Coils 64 and 65 are preferably intermeshed and wound on Aa 1/inch coil fer-mf coils es fend sifer'e mterresnd end W'ou'rid over coils 64 and 65, altlougli coils 64 and 65 may be intermeshed and wound on a separate c'oil form from coils 66 and 61. Coils 65 and 61 eac'liflias'lwthrdi coils 64 and 66 each has 12 tins. All coils are wound with l-gauge wire. One terminal of coil 64 is connected to terminal 6lL and 'rfi`trminal of coil 66 is connected to trlinihellfirOnetterminal of coil 65 is connected to terminal Il and one terminal of coil iiscrected to terminal I2. The remainder of Figure 3 is identical with Figure 1. H y

ebiyA altering phe/seiaviue'sj device may be reefenyerreaeedfe "eewit ,AM ena-'eurer e ifesideneeeiememf eeaneeeeeeras ener, te twef sistance element having respective values of resistance of the same order as the impedance of the input circuit of a television receiver, said values being such that the variable resistors may be adjusted to obtain substantially an impedance match between the antenna transmission wires and the receiver input circuit, first switch means arranged to selectively connect one of the terminals of said third variable resistor to either terminal of the first variable resistor, second switch means arranged to selectively connect another of the terminals of the third resistor to either terminal of the second Variable resistor and means connecting the third terminal of the third variable resistor to ground.

2. A television antenna matching device of the character described comprising a pair of output terminals, a second pair of terminals adapted to be respectively connected to the transmission Wires of a two wire television antenna system, a first variable resistor connected between one of said pair of output terminals and one of said second pair of terminals, a first condenser connected in series with said rst variable resistor between said one of said pair of output terminals and said one of said second pair of terminals, a second variable resistor connected between the other of said pair of output terminals and the other of said second pair of terminals, a second condenser connected in series with said second variable resistor between said other of said pair of output terminals and said other of said second pair of terminals, a third variable resistor having three terminals, said third variable resistor cornprising a resistance element connected at its ends match between the antenna. transmission wires and the receiver input circuit, rst switch means arranged to selectively connect one of the terminals of saidvthird variable resistor to either terminal of the rst variable resistor, second switch means arranged to selectively connect another of the terminals of the third variable resistor to either terminal of the second variable resistor, and circuit means, including a third condenser, connecting the remaining terminal of the third variable resistor to ground, said condensers having values of capacity to pass high frequencies and to block low frequencies.

3. A television antenna matching device of the character described comprising a pair of output terminals, a second pair of terminals adapted to be respectively connected to the transmission wires of a two-wire television antenna system, a first variable resistor connected between one of said pair of output terminals and one of said second pair of terminals, a second variable resistor connected between the other of said pair of output terminals and the other of said second pair of terminals, a third variable resistor having three terminals, said third variable resistor comprising a resistance element connected at its ends to two of said last-named terminals and a sliding tap engaging said resistance element and connected to the third of said last-named terminals, said rst and second variable resistors and said resistance element having respective values of resistance of the same order as the impedance of the input circuit of a television receiver, said values being such that the variable resistors may be adjusted to obtain substantially an impedance match between the antenna transmission wires and the receiver input circuit, first switch means arranged to selectively connect one of the terminals of said third resistor to either terminal of the first variable resistor, second switch means arranged to selectively connect another of the terminals of the third variable resistor to either terminal of the second variable resistor, circuit means connecting the remaining terminal of the third variable resistor to ground, and a transformer connected to said output terminals.

4. A television antenna matching device of the character described comprising a pair of output terminals, a second pair of terminals adapted to be respectively connected to the transmission wires of a two-wire television antenna system, a first variable resistor connected between one of said pair of output terminals and one of said second pair of terminals, a iirst condenser connected in series with said rst resistor between said one of said pair of output terminals and said one of said second pair of terminals, a second variable resistor connected between the other of said pair of output terminals and the other of said second pair of terminals, a second condenser connected in series with said second resistor between said other of said pair of output terminals and said other of said second pair of terminals, a third variable resistor having three terminals, said third Variable resistor comprising a resistance element connected at its ends to two of said last-named terminals and a sliding tap engaging said resistance element and connected to the third of said last-named terminals, said first and second variable resistors and said resistance element having respective values of resistance of the same order as the impedance of the input circuit of a television receiver, said values being such that the variable resistors may be adjusted to obtain substantially an impedance match between the antenna transmission wires and the receiver input circuit, first switch means arranged to selectively connect one of the terminals of said third resistor to either terminal of the rst variable resistor, second switch means arranged to selectively connect another of the terminals of the third resistor to either terminal of the second variable resistor, circuit means, including a third condenser, connecting the remaining terminal of the third variable resistor to ground, said condensers having values of capacity to pass high frequencies and to block low frequencies, and a transformer comprising four coils in inductive relation to each other, two of the coils being connected respectively to the pair of output terminals, and the remaining two coils being adapted to be respectively connected to the antenna posts of a television receiver.

RALPH R. WILLIAMS.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,824,801 Bouton Sept. 29, 1931 1,937,796 Smith et al. Dec. 5, 1933 1,998,322 Kaar Apr. 16, 1935 2,213,054 Schussler Aug. 27, 1940 2,296,920 Goodale Sept. 29, 1942 2,515,436 Babin July 18, 1950 

